The formulation of standards and specifications for biomaterials and instrumentation in dentistry requires the development and evaluation of standard test methods that can be used in different laboratories with reliability. The need for such control test methods for interlaboratory comparisons has long been recognized by such organizations as the American Society for Testing and Materials and the American National Standards Institute. The objectives of this proposal are to: 1. Develop new, or improve existing, test methods. 2. Compare the methods developed in objective one with existing methods where applicable. 3. Determine or relate significance of properties of materials with clinical performance. 4. Evaluate clinical significance of specification tests versus clinical performance.